This type of cryopreservation bag is disclosed in Patent Literature 1, for example. Here, the bag-shaped cryopreservation bag is formed by sandwiching and pressurizing two layered thermoplastic resin films between a supporter and an infrared transmitting solid heat radiating member (hereinafter merely referred to as “heat radiating member”) and radiating an infrared laser beam on both the films from a side of the heat radiating member to form a weld bead.
Regarding the sealing apparatus according to the invention, sealing of an opening portion of a cryopreservation container by thermal welding is disclosed in Patent Literature 2. Here, a plastic container main body for housing a biological sample is integrally provided with an opening portion and a tear portion and the opening portion is sealed by thermal welding with a sealer after the biological sample is housed into the container main body.